Pre-Nit Technology For Accelerated Vacuum Carburizing. Thomas Lord Sales Engineer- Vacuum Team SECO/WARWICK Corporation Meadville, PA

Transcription

1 Pre-Nit Technology For Accelerated Vacuum Carburizing Thomas Lord Sales Engineer- Vacuum Team SECO/WARWICK Corporation Meadville, PA

2 Definition of Pre-Nit Background on LPC Benefits of LPC & Pre-Nit vs. Atmosphere Carburizing How Does Pre-Nit Work Equipment Choices for Pre-Nit Generic Case Study Conclusion Definición de Pre-Nit Antecedentes sobre LPC Beneficios de la LPC & Pre-Nit vs. Atmósfera de carburación Cómo funciona Pre-Nit Opciones de equipo para Pre- Nit Estudio de caso genérico Conclusión

3 What Is Pre-Nitriding (Pre-Nit) Technology Qué es Pre-Nitriding (Pre-Nit) Tecnología Variation of LPC in Vacuum Furnace Use Of High Temperature To Boost Diffusion Coefficient Nitrides Diffused In Case To Restrict Grain Growth Reductions in Carburizing Cycle Time >50% (Case Depth Dependant) Variación de LPC en horno de vacío Uso de alta temperatura para aumentar el coeficiente de difusión Nitrides Difundido en caso para restringir el crecimiento del grano Reducción de tiempo de ciclo de carburación >50% (Dependiendo de la profundidad del caso)

4 TYPICAL Low Pressure Carburizing Cycle Ciclo de carburación típica baja presión Heat Up & Equalize Carburize and Diffuse Pump Down Quench Control: TEMPERATURE MASS FLOW TIME Temper

5 Shorten Carburizing Time Crecimiento de grano Maximize Carbon Potential Only go so far before carbide formation Preheat load prior to carburizing Increase Temperature without Intergranular Oxidation Grain Growth Temperature Temperatura Carburizing Time Tiempo de carburación Maximizar el potencial de carbono Ir sólo hasta antes de la formación de carburo y hollín Precalentar la carga antes de la cementación Aumento de la temperatura sin Oxidación intergranular Crecimiento de grano

6 INTERGRANULAR OXIDATION Gas carburizing Low Pressure Carburizing Carburación de Gas Bajo presión de Carburación Intergranular Oxidation Present Presente oxidación intergranular NO Intergranular Oxidation Present No Presente oxidación intergranular

7 Carburized layer Case Depth Uniformity Diesel Injection Nozzle Profundidad de la caja Uniformidad - Boquilla de inyección diesel Uniform Case Depth Blind Hole Ideal Penetration of Carburizing Gasses Profundidad de la caja uniforme Hoyo ciego La penetración ideal de carburación

8 PARTS ARE BRIGHT AND SHINY AFTER PROCESSING PARTES SON brillante y brillante DESPUÉS DE LA MISMA -Less distortion/ menos distorsión -Little to no post cleaning/poca o ninguna limpieza posterior GAS CARBURIZING Carburación GAS VACUUM CARBURIZING Carburación VACÍO

9 SAFETY & AUXILIARY EQUIPMENT A NO OPEN FLAMES NO FLAME SENSORS Evitar las llamas NO sensores de llama B NO ENDO GENERATOR NO COMPLICATED GAS CABINETS NO PARTS WASHERS (GAS QUENCH) NO ENDO GENERADOR NO gabinetes de gas COMPLICADO No hay piezas de arandelas (GAS) Quench 9

10 Grain Size/tamaño de grano With LPC SinLPC

11 SimCarb and SimVac software packages designed to easily build recipes for PreNitLPC process/ paquetes de software diseñados para construir fácilmente las recetas

12 LPC process LPC Cycle Example/ Ejemplo de ciclo

13 Residual Nitrogen Nitrogen effect Nitrogen diffusion in the depth Nano-scale nitrides - grain multi-nucleus - grain growth resistance Prenitriding only/ Prenitriding solamente Prenitriding + heat-up to 1000 o C/ Prenitriding + calor hasta Prenitriding +heat-up to 1000 o C + soak Prenitriding + calor hasta 1000 o C + empapar Complete process proceso completo

14 How Carburizing Gasses Are Introduced/ Cómo se introducen gases cementantes Carburizing Gas Flows Gas de carburación Flujos (C 2 H 2 +C 2 H 4 +H 2 ) Mass Flow Control Control de flujo de masa Uniform Distribution Distribución uniforme

15 Gas Quench Oil Quench a [W/m 2 K] Olej wolny Olej średni Slow oil Olej szybki Fast oil Middle oil 140% ω 100% ω 140% ω H 2 100% ω He 100% ω N p[bar]

16 Standard Furnaces HPGQ Hornos estándar- HPGQ 16

17 Standard Furnaces Double-chamber HPGQ Hornos estándar cámara de doble HPGQ 17

18 Standard Furnaces - Vertically oriented Hornos estándar - orientados verticalmente

19 Multi-chamber System: LPC + HPGQ Sistema de cámara múltiple: LPC + HPGQ 19

20 Double or Triple-chamber Oil quench Doble o Temple de aceite Triple cámara 20

21 TEMPEARTURE TEMPEARTURE Batch / Lote ECD:0.023 ; 880# charge 1 (first chamber) - Heat-up with PreNitLPC 2 (second chamber) - Oil Quenching 1885 F LPC 1 LPC F 1290 F F 2 Semi Continuous/ semi continuo ECD:0.023 ; 880# charge 535 TIME [min] 1 (first chamber) - Heat-up with Pre-Nitriding 2 (second chamber) - Low Pressure Carburizing 3 (thirdchamber) - Oil Quenching 1885 F 1615 F 1290 F LPC LPC LPC F TIME [min]

22 Case depth [mm] Carburizing time/ tiempo de carburación 925 o C 950 o C 980 o C 1000 o C 1020 o C 1040 o C h23m 0h57m 0h39m 0h30m 0h24m 0h19m h30m 3h50m 2h35m 2h00m 1h35m 1h15m h00m 15h10m 10h20m 8h00m 6h10m 4h50m Time relation 100 % 69 % 47 % 36 % 28 % 22 % 16MnCr5 steel carburizing time for the given case depth with a criteria of 0.35%C for ECD, as it relates to the process temperature.

23 16MnCr o C 18CrNiMo o C LPC 18,5 mm 26,2 mm PreNitLPC 15,6 mm 13,1 mm

24 Conclusion Conclusion FineCarbd & Pre-Nit LPCd is a proven technology in many industrial applications Implemented in single, double and multi-chamber vacuum furnaces with Oil & Gas Quench Applications in automotive, machine industries, and in commercial heat treatment shops Repeatable and reliable process and results controlled variables Supported by SimVaCd carburizing process simulator PreNitLPCd allows high temperature carburizing, over 1000C that significantly reduces process time and costs

25 THANK YOU For More Details SECO/WARWICK Corporation 180 Mercer St Meadville, PA T: F: